On Wednesday night, the case was turned over to detectives, who say they have promising leads. Meanwhile, a team of people are nursing the young dog back to health.

5-year-old "Enzo" has skin infections, severe mange, even a heart murmur. Staff at the Fresno Bully Rescue say it's the "worst they've seen." It was a property manager, who called the bully rescue after finding the pit bull in a west central neighborhood.

Becky Holly, who does Fundraising and Events for the Bully Rescue says, "He was in a backyard? there was some shade, some trees, there was a bowl that at one time had been used for water but was completely dry, no food anywhere to be found, feces everywhere."

The property manager told her, the utilities had been turned off; so Enzo likely hadn't had access to water for days on end. "I have no doubt that if somebody would have waited even a few days longer he would not have made it. In this heat, with no water, there's no way he could have survived."

Holly then called police. Detectives sent two officers and crime scene investigators to the bully rescue. On Wednesday night, they took pictures and tried to unravel the mystery into who left Enzo behind and why.

"This is someone who knew this dog was suffering and left it there to die."

She says, if there's one thing they've learned about Enzo, even a severe skin infection and heart problems can't keep him down. And she says, it's clearly not affecting his personality.

"I've never seen a dog in this condition, be this spry and have this much of a spirit and a will to live, he's an amazing animal."

Police say this will be a felony case, one that will likely lead to arrests. Detectives will further the case in the morning.